Comparability of two methods of estimating real-depth acuity

Vision-Related Parameters Affecting Stereopsis after Retinal Detachment Surgery

Even after successful surgery, the stereopsis of retinal detachment (RD) patients is inferior to that of normal subjects. However, it is unclear which visual dysfunction in the affected eye is responsible for the postoperative stereopsis impairment. This study included 127 patients after successful surgery for unilateral RD. Stereopsis, best-corrected visual acuity (BCVA), severity of metamorphopsia, letter contrast sensitivity and amount of aniseikonia were examined at 6-month postoperatively. Stereopsis was assessed using the Titmus Stereo Test (TST) and TNO stereotest (TNO). Postoperative stereopsis (log) in patients with RD were 2.09 ± 0.46 in the TST and 2.56 ± 0.62 in the TNO. Multivariate analysis with stepwise regression revealed postoperative TST was associated with BCVA, and TNO was associated with BCVA, letter contrast sensitivity, metamorphopsia and absolute values of aniseikonia. In a subgroup analysis that selected those with more impaired stereopsis, postoperative TST was associated with BCVA (p < 0.001), and TNO was associated with letter contrast sensitivity (p < 0.005) and absolute values of aniseikonia (p < 0.05) by multivariate analysis. Deterioration of stereopsis after RD surgery was affected by a variety of visual dysfunctions. The TST was affected by visual acuity, while the TNO was affected by contrast sensitivity and aniseikonia.

Relationship between stereopsis and vision-related quality of life in patients with branch retinal vein occlusion

Background

To investigate the relationship between stereopsis and vision-related quality of life (VR-QOL) in patients with branch retinal vein occlusion (BRVO) before and after treatment with intravitreal ranibizumab (IVR).

Methods

This prospective multicentred observational study included 37 patients undergoing IVR treatment for unilateral BRVO and 24 age-matched healthy controls.

Stereopsis was evaluated using the TNO stereo test (TNO) and Titmus stereo test (TST) every month, and the 25-item National Eye Institute Visual Function Questionnaire (VFQ-25) was administered at baseline, then at 3, 6 and 12 months after treatment.

Results

Time course of the changes in stereopsis and VR-QOL. IVR treatment significantly reduced central fovea thickness and improved both the TNO and the TST from 2 to 12 months (both p<0.05). Stereopsis before and after IVR injection in the eyes with BRVO were significantly worse than those in control subjects (TNO, p<0.001; TST, p<0.001). The VFQ-25 composite score significantly improved from 3 to 12 months after IVR treatment (p<0.05). Univariate analysis showed that the TNO score at baseline was significantly correlated with the VFQ-25 composite score at baseline and after treatment (p<0.05, p<0.05, respectively). TST score was not associated with the VFQ-25 composite score at baseline or after treatment.

Conclusions

Treatment with IVR for BRVO improved cystoid macular oedema, which was correlated to improved stereopsis, although not to the control level. The TNO score at baseline was associated with VR-QOL in patients with BRVO.

Visual functions affecting stereopsis in patients with branch retinal vein occlusion

PURPOSE

To quantify stereopsis and other visual functions in patients with unilateral branch retinal vein occlusion (BRVO) and to investigate vision-related parameters that affect stereopsis.

DESIGN

Prospective observational study.

SUBJECTS

Forty-five patients undergoing intravitreal ranibizumab (IVR) treatment for unilateral BRVO.

METHODS

We examined stereopsis using the Titmus stereo test (TST) and TNO stereotest (TNO), best corrected visual acuity (BCVA), letter contrast sensitivity, severity of metamorphopsia and degree of aniseikonia before and 6 months after IVR.

MAIN OUTCOME MEASURES

Visual functions that affect stereopsis.

RESULTS

Baseline stereopsis in patients with BRVO was 2.7 ± 0.6 (range, 1.6-3.5) in the TST and 2.8 ± 0.5 (range, 1.8-3.3) in TNO. TST and TNO scores were significantly correlated with BCVA and letter contrast sensitivity at baseline (P < 0.001) but not with other visual functions. IVR treatment significantly improved stereopsis, BCVA, and letter contrast sensitivity. After treatment, TST scores were significantly correlated with BCVA (P < 0.001), letter contrast sensitivity (P < 0.001), and aniseikonia (P < 0.01). TNO scores were significantly correlated with BCVA (P < 0.01) and letter contrast sensitivity (P < 0.01). TST and TNO scores after treatment were significantly correlated with BCVA at baseline (P < 0.01 for both).

CONCLUSIONS

Deterioration of stereopsis in patients with BRVO was associated with changes in visual acuity and contrast sensitivity after treatment. Initial visual acuity is a prognostic factor for posttreatment stereopsis.

Stereopsis and retinal microstructures following macular hole surgery

The aim of this prospective study was to evaluate the changes in stereopsis in patients who underwent vitrectomy for macular hole (MH) and assess the relationship between stereopsis and retinal microstructures. Fifty-two patients who underwent successful vitrectomy for unilateral MH and 20 control participants were recruited. We examined stereopsis using the Titmus Stereo Test (TST) and TNO stereotest (TNO), optical coherence tomography, and best-corrected visual acuity measurements, preoperatively, and at 3, 6, and 12 months postoperatively. As a result, preoperative and postoperative 3, 6, and 12-month values of stereopsis assessed by TST (log) were 2.7, 2.2, 2.2, and 2.2, respectively. TNO (log) were 2.8, 2.5, 2.4, and 2.4, respectively. Stereopsis in MH after surgery was significantly worse than that in normal participants (p < 0.001). Preoperative TST significantly correlated with MH size and defect length of external limiting membrane (ELM). Postoperative TST demonstrated significant correlation with the preoperative ELM defect length, and postoperative TNO was associated with the preoperative interdigitation zone defect length. Vitrectomy for MH significantly improved stereopsis, although not to normal levels. The ELM defect lengths, which approximately correspond to TST circles, are prognostic factors for postoperative stereopsis by TST. The interdigitation zone defect length, similar in size to the TNO index, is a prognostic factor for postoperative stereopsis by TNO.

Preoperative aniseikonia is a prognostic factor for postoperative stereopsis in patients with unilateral epiretinal membrane

PURPOSE

To investigate stereopsis and other visual functions in patients with unilateral epiretinal membrane (ERM) and to identify vision-related parameters affecting stereopsis.

METHODS

This prospective study included 63 consecutive patients who were scheduled to undergo vitrectomy for unilateral idiopathic ERM. We examined stereopsis (Titmus Stereo Test, TST; TNO stereotest, TNO), best-corrected visual acuity (BCVA), letter contrast sensitivity, severity of metamorphopsia, and degree of aniseikonia preoperatively and 6 months postoperatively.

RESULTS

Preoperatively, we observed significant correlation between TST scores and other vision-related parameters except severity of metamorphopsia and between TNO score and all the vision-related parameters. Multiple regression analysis showed that preoperative TST and TNO scores were significantly associated with the degree of aniseikonia (both P < 0.01). ERM surgery significantly improved stereopsis, BCVA, contrast sensitivity, and metamorphopsia, but not aniseikonia. Postoperatively, TST was significantly associated with BCVA, and TNO showed association with BCVA and aniseikonia. Postoperative TST and TNO scores showed significant correlation with preoperative aniseikonia (P < 0.005 and P < 0.001, respectively).

CONCLUSIONS

Impairment of stereopsis in patients with unilateral ERM was considered to be due to retinally induced aniseikonia. Aniseikonia did not improve by surgery, and preoperative aniseikonia can be a prognostic factor for postoperative stereopsis.

Vision-related parameters that affect stereopsis in patients with macular hole

This study evaluated stereopsis and other visual functions in patients with idiopathic macular hole (MH), and sought to identify vision-related parameters that affect stereopsis. In this prospective, consecutive, comparative study, 39 eyes of 39 patients with unilateral idiopathic MH were included. At baseline and at 6 months after MH surgery, we evaluated stereopsis, with the Titmus stereo test (TST) and TNO stereotest (TNO), best-corrected visual acuity (BCVA), letter contrast sensitivity, severity of metamorphopsia, as assessed using M-CHARTS, and extent of aniseikonia, by the new aniseikonia test. Preoperative stereopsis (log) in patients with MH were 2.72 ± 0.53 (range 1.9–4.1) in the TST and 2.82 ± 0.65 (range 1.8–3.9) in the TNO. Preoperative TST was significantly correlated with letter contrast sensitivity (p < 0.05), but not with the other visual functions. TNO showed significant correlation with letter contrast sensitivity (p < 0.05) and aniseikonia (p < 0.005). Preoperative TNO was associated with aniseikonia by multivariate analysis (p < 0.005). MH surgery significantly improved stereopsis, BCVA, letter contrast sensitivity, metamorphopsia, and aniseikonia. Postoperative TST and TNO was significantly associated with BCVA by multivariate analysis. Deterioration of stereopsis in MH patients is associated with contrast sensitivity and the degree of aniseikonia.

Stereopsis after successful surgery for rhegmatogenous retinal detachment

BACKGROUND

To evaluate stereopsis after successful surgery for unilateral rhegmatogenous retinal detachment (RD), and to investigate the relationship between stereopsis and clinical factors.

METHODS

In 75 patients after RD surgery and 28 age-matched normal subjects, stereopsis was measured using the Titmus Stereo Test (TST) and TNO stereotest. Clinical data were collected, including age, gender, circumferential dimension of retinal tears, area and duration of RD, macular status, surgical procedures, postoperative spherical equivalent, and logarithm of the minimum angle of resolution best-corrected visual acuity (logMAR BCVA), low-contrast visual acuity, postoperative lens status (phakia/pseudophakia), and presence of postoperative epiretinal membrane (ERM), to determine the factors related to stereopsis.

RESULTS

Stereopsis in patients after surgery was significantly worse than normal subjects (p < 0.0001). Stereopsis in TST was significantly correlated with the area of RD (p < 0.005), difference of postoperative spherical equivalent between two eyes (p < 0.05), postoperative logMAR BCVA (p < 0.005), difference of postoperative logMAR BCVA between two eyes (p < 0.01), and low-contrast visual acuity (p < 0.05). Stereopsis in TNO stereotest showed significant association with postoperative logMAR BCVA (p < 0.05). Stereopsis in both stereotests were significantly worse in patients with macula-off RD than macula-on RD (p < 0.005, p < 0.01 respectively). No significant relationship was found between stereopsis and other factors. Multiple regression analysis revealed that macular status (on/off) had a significant correlation with both stereopsis in TST and TNO stereotest (p = 0.028, p = 0.019 respectively), whereas other clinical parameters were not relevant.

CONCLUSIONS

Stereopsis is significantly deteriorated in patients after RD surgery than in normal subjects. Stereopsis was associated with the difference in refraction between two eyes, postoperative visual acuity and contrast sensitivity, and preoperative macular status.